Megan Fox once suggested that appearing in Transformers movies didn't involve much real acting. It would therefore be easy to suggest she has only herself to blame after news broke that somebody else will get to be Shia LaBoeuf's squeeze in the next instalment of Michael Bay's horrendous series. If your job is just to look pretty, or scream and run around on cue while hundreds of unidentifiable giant CGI machines with silly voices chicane around the screen, there are myriad actors who can provide the same service. It also possible to suggest that comparing Bay to "Hitler" may not have helped Fox's cause.Look around the web today and it's clear that most bloggers think Fox's regular ill-advised comments to the press are to blame for her departure. The consensus seems to be that Bay, himself no slouch in the foot in mouth department, simply had enough of his young star's attitude and decided to plump for somebody new.

Such a conclusion ignores Fox's own statement suggesting that it was she who called time on her Transformers sojourn. The truth may never be discovered, but it's worth bearing in mind that Bay himself can allegedly be a difficult man to work with on set.

Of course, the reality of the situation is that Fox's departure will make not one jot of difference to Transformers III. It will still be a brain-straining near three-hour journey into the mind of a director who makes films for people with the attention span of a goldfish. It will still make film critics wish that they taken the advice of their school careers advisor and opted for a job in dentistry, and it will still rack up hundreds of millions of greenbacks for studio Paramount without breaking a sweat. There will just be a different hottie in the hot seat (sources are suggesting Gemma Arterton, who can actually act, but won't need to).

What next for Fox? Well, she's got comic book movie Jonah Hex coming up, a western-themed action adventure starring Josh Brolin as a scarred former confederate soldier with supernatural powers. A couple of new TV spots have just been released, which don't look too bad, but the movie itself has some bad buzz around it. Amateur reviews from test screenings have been almost universally negative, and Fox herself is coming in for some of the worst criticism. "She plays Leila, a prostitute with no back story," wrote one disappointed fan. "All we know about her is that she saves all her money to buy a piece of land and that she and Jonah Hex have feelings for each other. Leila is really only in the movie for about 10 minutes, and [Fox's] acting was terrible."

Hex certainly doesn't look to be the type of film which is going to convince moviegoers or critics that Fox is the real deal as an actor. I didn't think she was too bad at all as a snide cheerleader type who is transformed into a man-eating succubus in Diablo Cody's Jennifer's Body. And yet that movie failed to live up to early indications that it might be the new Heathers, largely because Fox is not possessed of anything approaching the charisma and insouciant cool of a Christian Slater.

Is there a touch of schadenfreude, or even misogyny, about the apparent mass hatred of this striking but not obviously talented young actor? Could it be that her looks are actually holding her career back? If that is the case, then she might be well-advised to do a Cameron Diaz, and find herself a couple of smart indie movies in which she can prove she has the thespian chops. Forthcoming drama Passion Play, in which Fox will star opposite Mickey Rourke, looks to be that kind of movie. And if that doesn't work out, well ... I hear they're making a sequel to GI Joe.